Path `docs/current` no longer returns latest/current version of docs

[cloudymax]

Quite a few places around the cnpg ecosystem reference "https://cloudnative-pg.io/docs/current/" which seems to have stopped working. Replacing current with a valid release eg: 1.28 will get you to a real page but otherwise you'll get a blank page.

Might be related to #21 since I've seen a few documentation/current/ occurrences as well.

Cheers!

[gbartolini]

This commit should put a temporary patch with client-side HTTP redirects: cloudnative-pg/cloudnative-pg.github.io@c4ff5dc

Hopefully we will be able to work on more powerful and accurate server-side redirects through the CNCF.

[gbartolini]

I have tested the redirects with:

• https://cloudnative-pg.io/documentation/current/
• https://cloudnative-pg.io/documentation/1.28/
• https://cloudnative-pg.io/documentation/1.27/

And they all redirect users to the new pages. Even individual pages should be redirected. Not sure if search engines interpret this directive (they should).